JPH01202109A - Branch connecting box for wire harness - Google Patents

Abstract

PURPOSE:To manufacture the miniature product of light weight at a low cost, by using a bus bar and a flexible printed board, for an electric wiring in a terminal case connected to a wire harness. CONSTITUTION:In a terminal case 1 connected to a wire harness, a bus bar 2 and an FPC(flexible printed board) 5 are used to perform electric wiring. A bus bar terminal 3a is connected to the bus bar 2 via a connector housing 4. An FPC terminal 3b is connected to the FPC 5 via a connector housing 4' by being reinforced with a reinforcing plate 6. As a result, the case 1 of a branch connecting box is miniaturized and the weight is lightened, and the mounting of an electronic component part can be performed, and a manufacturing cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a branch connection box for branching wiring harnesses mainly used in automobiles.

[Conventional technology]

As well-known branch junction boxes for wire harnesses, there are those that connect the terminals for connection with the wire harness with a bus bar, those that connect via electric wires, and those that connect via a conductor circuit on a printed circuit board. Figure 4 shows busbar wiring, in which busbars 2 are housed in multiple layers within case 1 of a junction box, and connection terminals 3 made by bending the ends of the busbars as shown in figure 5 are formed integrally with case 1. The connector is connected to the terminal on the wire harness side within the connector housing part 4.

[Problem to be solved by the invention]

Due to design and manufacturing constraints, branch junction boxes using busbar wiring have a large surface area and large thickness, making it difficult to measure the increase in the number of twisted circuits in automobiles where installation space is limited. have.

On the other hand, connection boxes for electric wires are complicated and expensive to manufacture, and those using printed circuit boards have problems such as not allowing large currents to flow through them.

However, the electrical wiring in automobiles has become increasingly complicated due to the increase in signal lines due to the recent advances in high-grade electronic control. However, there is no such thing.

Therefore, there is a need for a branch connection node for harness wiring that is small, lightweight, has a large number of circuits, and is inexpensive, eliminating the above-mentioned problems.

An object of the present invention is to realize and provide a junction box that meets such demands.

(Means for Solving the Problems) The branch junction box of the present invention uses a bus bar and a flexible printed circuit board (hereinafter referred to as FPC) in combination for electrical wiring within the case between terminals for connection with a wire harness. It has the following characteristics.

This VT box can increase added value by incorporating functional parts that constitute an electronic control circuit into the FPC circuit.

In addition, some of the terminals for connection are FPC terminals made by reinforcing a part of FPC, and on the other hand, the case of the connection box has an FPC terminal for connecting the connector at the end of the wire harness.
By integrally providing a housing for a dedicated connector for each of the PC terminal, a passbar terminal, or a common connector that mixes both terminals, the structure can be further simplified, downsized, and lightened.

[Effect]

The busbar has a large current 1j1i capability, while the FPC
It is small and lightweight, has a high degree of freedom in deformation, and has the advantage of being able to create a large number of circuits in a small area. According to the present invention, since both of these features are fully utilized, it is possible to realize an inexpensive branch connection Vtn that is small, lightweight, and has a large number of circuits.

In other words, wire harness circuits for automobiles, for example, which are connected via a branch junction box, contain a mixture of circuits with a high current of several tens of amperes to ones with a small current of only several milliamperes, and moreover, wire harness circuits with advanced electronic control How small is the car? S. Contains many current signal lines, but if you connect the large number of medium and small current parts with FPC, you can reduce the number of bus bars that are used for large currents, which are factors that increase size, weight, and cost. At the same time, it becomes possible to increase the number of circuits connected by one connection box.

〔Example〕

An embodiment of the present invention will be described based on FIGS. 1 to 3.

Figure 1 schematically shows the overall view of the branch junction box, where 1 is a case, 2 is a bus bar, 3a and 3b are connection terminals, and 4 is a connector housing integrally formed at an appropriate location on case 1. , 5 is an FPC housed in the case 1 together with the bus bar.

The bus bar 2 is incorporated into the case 1 so as not to move by a known appropriate method such as providing a groove on the inner surface of the case and fitting it into the groove, but the FPC 5 may be fixed as necessary.

Next, the terminal 3a is a bus bar terminal connected to the bus bar 2, and in the illustrated connection box, it is arranged in the connector housing 4 dedicated to large current. On the other hand, the terminal 3b is an FPC terminal provided integrally with the FPC 5 and arranged in a connector housing exclusively for medium/low current. This FPC terminal 3b lacks mechanical strength as it is and cannot be used as a connector terminal.Therefore, reinforcement measures as shown in FIG. 2 or 3 are taken. The solution shown in FIG. 2 is to provide a reinforcing plate 6 integral with the case 1 inside the connector housing 4, and to wrap the terminal 3b around this reinforcing plate.

In addition, the measure shown in FIG. 3 is to provide a lance 7 on the inner surface of the connector housing 4, and use the lance 7 to prevent the F which tries to retreat when inserting the connector terminal 11 of the wire harness 10.
The PC terminal 3b is held in place, and the mutual contact pressure between the terminals 3b and 11 is maintained using the housing 4 as a reinforcing material. In addition, a structure often used in FPC, that is, a structure in which a reinforcing plate is attached to the back side of the FPC terminal 3b and this reinforcing plate is locked inside the housing, can also be used to give the function as a connector terminal to the FPC terminal 3b. .

Note that the connector housing 4 may have the bus bar terminals 3a and the FPC terminals 3b mixed in one housing for common use.

Further, the bus bar 2 and the FPC 5 may be electrically connected as necessary.

Furthermore, when creating a junction box with a built-in electronic control circuit, it is most desirable to mount the electronic functional components directly on the FPC 5, but it is best to mount the functional components on a separately prepared FPC or printed circuit board and connect it to the FPC 5. Even with this method, a junction box with the same functions and high added value can be obtained.

The branch junction box of the present invention configured as described above has 74 twisted circuits, whereas the existing junction box with only busbar wiring has 3 to 4 layers of busbars, for example. , assuming that the maximum current of FPC is 2.5A,
35 circuits can be provided on one FPC, and the number of busbar layers is reduced to two, making it smaller, lighter, and lower in cost.

〔effect〕

As described above, according to the present invention, the number of bus bars used is reduced as much as possible by using bus bars and FPC in combination for electrical wiring between connection terminals, and the space is saved by fully utilizing the features of FPC. Since a sufficient number of circuits is secured without increasing the number of circuits, it is possible to realize a branch junction box that is small, lightweight, has a large number of circuits, and is inexpensive.

Furthermore, since the use of FPC makes it easy to mount electronic components, it is also possible to realize a high value-added connection box with a built-in electronic control circuit at a low cost.

[Brief explanation of the drawing]

Fig. 1 is a sectional view schematically showing an example of a branch junction box of the present invention, Figs. 2 and 3 are sectional views showing an example of a reinforcing structure for an FPC terminal, and Fig. 4 is a sectional view of a conventional branch junction box. FIG. 5 is a cross-sectional view schematically showing details of a terminal formed of a bus bar and a connector housing housing the terminal. 1... Case, 2... Bus bar, 3a... Bus bar terminal, 3b...
・FPC terminal, 4...Connector housing, 5...FPCl 6...Reinforcement plate, 7...Lance.

Claims (3)

[Claims] (1) A branch junction box for a wire harness in which a bus bar and a flexible printed circuit board are used together for electrical wiring inside the case between terminals for connection to the wire harness. (2) The branch connection box for a wire harness according to claim (1), wherein functional parts constituting an electronic control circuit are incorporated into the circuit of the flexible printed circuit board. (3) Some of the above connection terminals are FPC terminals made by reinforcing a part of the flexible printed circuit board, while the above case of the connection box is dedicated to PFC terminals and bus bar terminals. Claim (1) or (1) in which the housing of the connector or the common connector in which both terminals are mixed is provided integrally.
The branch connection box for wire harnesses described in 2).